package com.litongjava.utils.audio.wav;


import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * @author litong
 * @date 2019年2月20日 上午9:44:59
 * @see 02.nve-java-api.doc
 */
public class WAVUtil {
	public static void pcmToWav(String pcmFilename, String weveFilename, long mSampleRate) {
		int mBufferSize = 1024;

		FileInputStream in;
		FileOutputStream out;
		long totalAudioLen;
		long totalDataLen;
		long longSampleRate = mSampleRate;
		int channels = 1;
		long byteRate = 16 * mSampleRate * channels / 8;
		byte[] data = new byte[mBufferSize];
		try {
			in = new FileInputStream(pcmFilename);
			out = new FileOutputStream(weveFilename);
			totalAudioLen = in.getChannel().size();
			totalDataLen = totalAudioLen + 36;

			writeWaveFileHeader(out, totalAudioLen, totalDataLen, longSampleRate, channels, byteRate);
			while (in.read(data) != -1) {
				out.write(data);
			}
			in.close();
			out.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void writeWaveFileHeader(FileOutputStream out, long totalAudioLen, long totalDataLen,
			long longSampleRate, int channels, long byteRate) throws IOException {
		byte[] header = new byte[44];
		header[0] = 'R'; // RIFF/WAVE header
		header[1] = 'I';
		header[2] = 'F';
		header[3] = 'F';
		header[4] = (byte) (totalDataLen & 0xff);
		header[5] = (byte) ((totalDataLen >> 8) & 0xff);
		header[6] = (byte) ((totalDataLen >> 16) & 0xff);
		header[7] = (byte) ((totalDataLen >> 24) & 0xff);
		header[8] = 'W';
		header[9] = 'A';
		header[10] = 'V';
		header[11] = 'E';
		header[12] = 'f'; // 'fmt ' chunk
		header[13] = 'm';
		header[14] = 't';
		header[15] = ' ';
		header[16] = 16; // 4 bytes: size of 'fmt ' chunk
		header[17] = 0;
		header[18] = 0;
		header[19] = 0;
		header[20] = 1; // format = 1
		header[21] = 0;
		header[22] = (byte) channels;
		header[23] = 0;
		header[24] = (byte) (longSampleRate & 0xff);
		header[25] = (byte) ((longSampleRate >> 8) & 0xff);
		header[26] = (byte) ((longSampleRate >> 16) & 0xff);
		header[27] = (byte) ((longSampleRate >> 24) & 0xff);
		header[28] = (byte) (byteRate & 0xff);
		header[29] = (byte) ((byteRate >> 8) & 0xff);
		header[30] = (byte) ((byteRate >> 16) & 0xff);
		header[31] = (byte) ((byteRate >> 24) & 0xff);
		header[32] = (byte) (2 * 16 / 8); // block align
		header[33] = 0;
		header[34] = 16; // bits per sample
		header[35] = 0;
		header[36] = 'd';
		header[37] = 'a';
		header[38] = 't';
		header[39] = 'a';
		header[40] = (byte) (totalAudioLen & 0xff);
		header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
		header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
		header[43] = (byte) ((totalAudioLen >> 24) & 0xff);
		out.write(header, 0, 44);
	}
}